Eraser device



Dec. 28, 1943. J. s DQRNER 2,337,979

ERASER DEVICE Filed Dec. 18, 1942 .l fk5/677520: kfaQ?? @Jar/762;

Patented Dec. 28, 1943 nassen nmol:

Jean S. Dorner, Evanston, Ill. Application December '1a. 1942 sei-m1 No. 469,416

* (ci. 12a-ss) 6 Claims.

My invention relates to eraser devices of the type comprising a casing, preferably of elongated form as in the case of lead pencils, which in use is held by the user at an angle oblique to the surface on which the erasure is to be effected, the casing forming a housing and supporting means for an eraser element which protrudes therefrom into a position for use; and more particularly, though not exclusively, to such type of eraser devices in which provision is made for mechanically feeding the eraser element into position for use as it is worn away.

One of my objects is to provide an eraser device of such construction that eraser elements of such relatively small cross-sectional size as to render them susceptible to fracture unless protected, may be used with the minimum likelihood of breakage in the erasing operations, and by which the protruding ends of the eraser elements may be firmly held against wobbling in use; all to the end of providing a highly satisfactorily functioning device and conserving the material of which the eraser elements are formed; and other objects as will be manifest from the following description. .l

Referring to the accompanying drawing:

Figure 1 is a View in side elevation of an eraser device constructed in accordance with my invention, the device beingshown as held in the hand of the operator in'pos'ition for erasing a surface to which the device is shown as applied.

Figure 2 is a view in longitudinal sectional elevation of the device of Figure 1.

Figure 3 is a section taken at the line 3-3 on Figure 2 and viewed in the direction of the arrows; and

Figure 4 is a section taken at the line 4-4 on Figure 2 and viewed in the direction of the arrows.

The eraser device, in accordance with the preferred illustrated embodiment of my invention, comprises an elongated casing generally of a form as in the case of a lead pencil, and shown as formed of two relatively rotatable sections 5 and 6, the upper section 5 which is hollow, being telescoped at the circular socket I therein, with a reduced circular boss-forming portion 8 of the other section 6, affording a rotatable connection between the two casing sections.

The lower section 6 has a longitudinal bore 9 in which the eraser element shown at ID and provided of stick form from any suitable erasing material such as for example that commonly used for erasers, is disposed to protrude through the lower open end of the casing in position for use.

The inner surface of the bore 9 is preferably provided ,with any suitable means for ensuring against accidental sliding of the eraser element from the casing, such as for example those shown and comprising a plurality-of parallel ribs II on the surface of the wall of the bore and extending lengthwise thereof and serving by their embedment in the eraser element Ill to prevent undue sliding of the latter.

The device also comprises means for mechanically extruding the eraser element Il! through the lower end of the casing to present fresh p0rtions of the eraser element for use as the latter wears away. The particular means shown for this purpose comprise a screw-rod I2 in the upper casing section 5 aligned with the eraser element I Il and screwed in a threaded opening I 3 in the boss 8. The rod I2 engages at its lower end with the adjacent end of the eraser element III, as shown, and serves, when rotated in the section 5 in one direction, to force the eraser element through the lower end of the lower casing" section 6 and as a backing member to hold the eraser element in extruded position in the use of the eraser device. 'I'he means shown for rotating the rod l2 comprise a hex-head I4, rigid on the upper end of the rod I2 and located in the longitudinally extending chamber I5 of the upper casing section 5. Thechamber I5 is of hex Ashape in cross-section throughout its length, providing a means for rotating the rod I2 by rotating the section 5 on the section 6, the t of the head I4 with the walls of the chamber I5 being suciently free as to permit the head to slide in the casing section 5 in the rotation of the latter.

According to the particular construction shown, the lower casing section 6, at its lower end portion, is of tapered conical form as shown at I5 and has projecting downwardly therefrom a cylindrical tubular protective shield I1 which is concentric with the longitudinal axis of the eraser device and in which the extruded end vof the eraser element I0 snugly ts, the shield portion I1 and the conical portion I5 being by way of example and by preference formed as a one piece structure as shown.

'I'he lower end face of the shield I1 is cutaway or relieved, as for example by beveling it as represented at I 8, to permit contact of the extruded end of the eraser element I0 with the surface to be erased, as for example that shown at I9, with the minimum protrusion of the eraser element beyond the end of the casing and without rubbing contact of the shield I1 with said surface, in the holding oi' the eraser device bythe operator at the desired acute angle to the plane of the surface on which the erasure is to be made, as for example as shown in Figure 1 which represents the device as held in use at an angle of about 30 to said surface. causing the shield portion I1 to shield and support the eraser element in the erasing operation, thereby preventing the breaking or spalling of the protruded portion of the eraser element.

As will be understood from the foregoing, practically all of the stresses imposed on the protruded portion of the eraser element by the force exerted by the operator in using the eraser device at an acute angle to the surface on which the erasure is to be eiiected, fall within the area comprised b-y the shield I1 and particularly as the extent of protrusion oi' the eraser element beyond the shield need be only slight, the possibility ol' breaking or spalling of the protruded portion of the eraser element even when of relatively small cross-sectional area, as for example and preferably of about %4.inch diameter, is reduced to the minimum.

While I have illustrated and described a particular embodiment of my invention, I do not wish to be understood as intending to limit it thereto as the s ame may be variously modiiied and altered, and the invention embodied in other forms of structure without departing from the sprit of my invention.

I claim:

1. An eraser device comprising a casing for an eraser element of approximately 964" in diameter and having a beveled end with its lower end portion terminating in a shield portion having an open end coincident with the longitudinal axis of the device and through which said eraser element protrudes at its beveled end, portions of the open end of said shield portion extendingto different points along the device, said eraser element `being so positioned axially in said casing that the highest portion of the beveled part of said eraser element does not extendsubstantially below the lowest portion ofv the open end of said shield portion.

2. An eraser device comprising a casing for an eraser element of approximately Wa in diameter and having a beveled end with its lower end portion terminating in a shield portion having an open end coincident with the longitudinal axis of the device and through which said eraser element protrudes at its beveled end, the open end of said shield portion being cut away at an angle oblique to said longitudinal axis, said eraser element being so positioned axially in said casing that the highest portion of the beveled part of said eraser element does not extend substantially below the lowest portion of the open end of said shield portion.

3. An eraser device comprising a casing for an eraser element oi'approximately 964" in diameter and having a beveled end with its lower end portion terminating in a shield portion having an open end coincident with the longitudinal axis of the device and through which said eraser element protrudes at its beveled end, the open end of said shield'portion being cut away at such an angle, oblique to said longitudinal axis, as to cause the terminal edge of said shield portion to be disposed substantially parallel with the surface on which an erasure is to be eliected, in the manipulation of the device in the erasing operation, while held at an angle oblique to said surface, said eraser element being so positioned axially in said casing that the highest portion oi' the beveled part of said eraser element does not extend substantially below the lowest portion of the open end of said shield portion.

4. An eraser device comprising a casing for an eraser element of approximately %4" in diameter and having a beveled end with its lower end terminating in a tubular shield portion which surrounds said eraser element and through which said element protrudes at its beveled end, portions of the open end of said shield portion extending to different distances along the device, said eraser element being so positioned axially in said casing that the highest portion of the beveled part of said eraser element does not extend substantially below the lowest portion of the open end of said shield portion.

5. An eraser device comprising a 'casing for an eraser element of approximately 9/34" in diameter and having a beveled end with its lower end terminating in a tubular shield portion concentric throughout its length with the longitudinal axis of the device and from which said eraser element protrudes at its beveled end, portions of the open end of said shield portion extending to different points along the device, said eraser element being so positioned axially in said casing that the highest portion of the beveled part of said eraser element does not extend substantially below the lowest portion of the open end of said shield portion.

6. An eraser device comprising a casing for an eraser element-of approximately %4," in diameter and having a beveled end with its lower end terminating in a tubular shield portion concentric throughout its length with the longitudinal axis of the device and from which said eraser element protrudes at its beveled end. the open end of said shield portion being cut away at an angle oblique to said longitudinal axis, said eraser element being so positioned axially in said casing that the highest portion of the beveled part of said eraser element does not extend substantially below the lowest portion of the open end of said shield portion.

JEAN S. DORNER. 

